package com.lrkj.back.vo.json;

/*
 * Copyright (c) 2002 JSON.org
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * The Software shall be used for Good, not Evil.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

import java.util.Locale;
import java.util.Map.Entry;

/**
 * Convert an HTTP header to a JSONObject and back.
 * 
 * @author JSON.org
 * @version 2015-12-09
 */
public class HTTP {

    /** Carriage return/line feed. */
    public static final String CRLF = "\r\n";

    /**
     * Convert an HTTP header string into a JSONObject. It can be a request
     * header or a response header. A request header will contain
     * 
     * <pre>
     * {
     *    Method: "POST" (for example),
     *    "Request-URI": "/" (for example),
     *    "HTTP-Version": "HTTP/1.1" (for example)
     * }
     * </pre>
     * 
     * A response header will contain
     * 
     * <pre>
     * {
     *    "HTTP-Version": "HTTP/1.1" (for example),
     *    "Status-Code": "200" (for example),
     *    "Reason-Phrase": "OK" (for example)
     * }
     * </pre>
     * 
     * In addition, the other parameters in the header will be captured, using
     * the HTTP field names as JSON names, so that
     * 
     * <pre>
     *    Date: Sun, 26 May 2002 18:06:04 GMT
     *    Cookie: Q=q2=PPEAsg--; B=677gi6ouf29bn&b=2&f=s
     *    Cache-Control: no-cache
     * </pre>
     * 
     * become
     * 
     * <pre>
     * {...
     *    Date: "Sun, 26 May 2002 18:06:04 GMT",
     *    Cookie: "Q=q2=PPEAsg--; B=677gi6ouf29bn&b=2&f=s",
     *    "Cache-Control": "no-cache",
     * ...}
     * </pre>
     * 
     * It does no further checking or conversion. It does not parse dates. It
     * does not do '%' transforms on URLs.
     * 
     * @param string
     *            An HTTP header string.
     * @return A JSONObject containing the elements and attributes of the XML
     *         string.
     * @throws JSONException
     */
    public static JSONObject toJSONObject(String string) throws JSONException {
        JSONObject jo = new JSONObject();
        HTTPTokener x = new HTTPTokener(string);
        String token;

        token = x.nextToken();
        if (token.toUpperCase(Locale.ROOT).startsWith("HTTP")) {

            // Response

            jo.put("HTTP-Version", token);
            jo.put("Status-Code", x.nextToken());
            jo.put("Reason-Phrase", x.nextTo('\0'));
            x.next();

        } else {

            // Request

            jo.put("Method", token);
            jo.put("Request-URI", x.nextToken());
            jo.put("HTTP-Version", x.nextToken());
        }

        // Fields

        while (x.more()) {
            String name = x.nextTo(':');
            x.next(':');
            jo.put(name, x.nextTo('\0'));
            x.next();
        }
        return jo;
    }

    /**
     * Convert a JSONObject into an HTTP header. A request header must contain
     * 
     * <pre>
     * {
     *    Method: "POST" (for example),
     *    "Request-URI": "/" (for example),
     *    "HTTP-Version": "HTTP/1.1" (for example)
     * }
     * </pre>
     * 
     * A response header must contain
     * 
     * <pre>
     * {
     *    "HTTP-Version": "HTTP/1.1" (for example),
     *    "Status-Code": "200" (for example),
     *    "Reason-Phrase": "OK" (for example)
     * }
     * </pre>
     * 
     * Any other members of the JSONObject will be output as HTTP fields. The
     * result will end with two CRLF pairs.
     * 
     * @param jo
     *            A JSONObject
     * @return An HTTP header string.
     * @throws JSONException
     *             if the object does not contain enough information.
     */
    public static String toString(JSONObject jo) throws JSONException {
        StringBuilder sb = new StringBuilder();
        if (jo.has("Status-Code") && jo.has("Reason-Phrase")) {
            sb.append(jo.getString("HTTP-Version"));
            sb.append(' ');
            sb.append(jo.getString("Status-Code"));
            sb.append(' ');
            sb.append(jo.getString("Reason-Phrase"));
        } else if (jo.has("Method") && jo.has("Request-URI")) {
            sb.append(jo.getString("Method"));
            sb.append(' ');
            sb.append('"');
            sb.append(jo.getString("Request-URI"));
            sb.append('"');
            sb.append(' ');
            sb.append(jo.getString("HTTP-Version"));
        } else {
            throw new JSONException("Not enough material for an HTTP header.");
        }
        sb.append(CRLF);
        for (final Entry<String, ?> entry : jo.entrySet()) {
            final String key = entry.getKey();
            if (
                !"HTTP-Version".equals(key) && !"Status-Code".equals(key) && !"Reason-Phrase".equals(key)
                        && !"Method".equals(key) && !"Request-URI".equals(key)
                        && !JSONObject.NULL.equals(entry.getValue())
            ) {
                sb.append(key);
                sb.append(": ");
                sb.append(jo.optString(key));
                sb.append(CRLF);
            }
        }
        sb.append(CRLF);
        return sb.toString();
    }
}
